Determination of Strength and Deformation Parameters of Remolded Clays by Falling Cone and Veyn Tests

Öz

In practice, the shear vane test is used to predict the undrained shear strength of remolded and undisturbed clay soils. The undrained shear strength could also be estimated for remolded soils by the fall cone test. However, the determination of undrained shear strength by this test requires a very significant factor which is referred to as fall cone factor. The drained internal friction angle could be obtained by using the fall cone factor, calibrated in accordance with experimental results and the values of undrained shear strength calculated for different water contents and void ratios at critical state. In this study, compressibility and strength parameters were determined practically on remolded samples of cohesive soils with different index proporties by using the methods proposed in the literature. In addition, the applicability of the method used was evaluated for the same soil by comparing the compressibility and strength parameters obtained from oedometer and triaxial compression tests.

Anahtar Kelimeler

• Remolded clay,critical state parameters,fall cone test

Yoğrulmuş Killerde Dayanım ve Deformasyon Parametrelerinin Düşen Koni ve Veyn Deneyleri ile Belirlenmesi

Öz

Yoğrulmuş ve örselenmemiş killi zeminlerin drenajsız kayma mukavemeti pratik olarak veyn deneyi ile belirlenebilmektedir. Diğer bir pratik deney olan düşen koni deneyi ile de yoğrulmuş kohezyonlu zeminlerin drenajsız kayma mukavemetine geçiş yapılabilmektedir. Ancak bu geçiş sırasında bir düşen koni faktörüne (K) ihtiyaç duyulmaktadır. Deneysel verilerle kalibre edilen koni faktörü, farklı su muhtevaları için hesaplanan drenajsız kayma mukavemetleri ve kritik durumdaki boşluk oranları kullanılarak drenajlı kayma mukavemeti açısına geçiş yapılmaktadır. Bu çalışmada, yoğrularak hazırlanan farklı endeks özelliklere sahip kohezyonlu zemin örnekleri üzerinde, literatürde önerilen yöntemlerden faydalanılarak sıkışabilirlik ve mukavemet parametreleri pratik olarak belirlenmiştir. Aynı zeminler için ödometre ve üç eksenli basınç deneylerinden ile elde edilen sıkışabilirlik ve mukavemet parametreleri ile karşılaştırılarak uygulanan yöntemin kullanılabilirliği değerlendirilmiştir.

Anahtar Kelimeler

• Yoğrulmuş kil,kritik durum parametreleri,düşen koni deneyi

Kaynakça

1. [1] Farias, M.M., LIano-Serna, M.A., Simple Methodology to Obtain Critical State Parameters of Remolded Clays Under Normally Consolidated Conditions Using the Fall-Cone Test, Geoteknical Testing Journal,39, 5, 855-864, 2016.
2. [2] Koumoto, T., Houlsby, G.T., Theory and Practise of the Fall-Cone Test, Geotechnique, 51, 8,701-712,2001.
3. [3] Kumapley, N., Boakye, S.Y., The Use of Cone Penetrometers for the Determination of the Liquid Limitsof Soil Flow Plasticity, Prof. 7th Regional Conf. for Africa on Soil Mech. Found. Engng, 167-170, 1980.
4. [4] Hansbo, S., A New Approach to the Determination of the Shear Strengh of Clay by the Fall–Cone Test, Royal Swedish Geoteknical Instıtıte, Linköping, 7-47, 1957.
5. [5] Wood, D.M., Wroth, C.P., The Use of Cone Penetrometer to Determine the Plastic Limit of Soil, Ground Eng., 11, 3, 37, 1978.
6. [6] Casagrande, A., Notes on the Design of the Liquid Limit Device, Geotechnique, 8, 2, 84-91, 1958.
7. [7] Karlsson, R., Suggested Improvements in the Liguid Limit Test With Referance to Flow Properties of Remolded Clays, Presented at 5th Internatıonal Conferance on Soil Mechanics and Foundatıon Engineering, Paris, 171-184, 1961.
8. [8] Whyte, I.L., Soil Plasticity and Strength: A New Approach Using Extrusion, Ground Eng. 15, 1, 16-24,1982.

9. [9] Wood, D.M., Some Fall-Cone Tests, Geotechnique 35, 1, 64-68, 1985.
10. [10] Gardiner, E.O., Part II Project Report, Cambridge University Engineering Department, United Kingdom, 1982.
11. [11] Ayadat, T., Hanna, A., Identıfication of Collapsible Soil Using the Fall Cone Apparatus,Geoteknical Testing Journal, 30, 4, 1-12, 2007.
12. [12] Zentar, R., Abriak, N.E., Dubois, V., Fall Cone Test to Characterize Shear Strength of Organic Sediments, ASCE Geotech. Geoenviron. J.,135, 1, 30-53, 2009.
13. [13] O’Kelly, B.C., Atterberg Limits and Remolded Shear Strengh-Water Content Relationships, Geotech. Test. J., 36, 6, 1-6, 2013.
14. [14] LIano-Serna, M.A., Experimental and Numerıcal Study of Geotechnical Problems Using the Material Point Method, PhD, Faculdade De Tecnologıa Departamento De Engenharia Cıvıl E Ambiental,Unıversidade De Brasılıa, 2016.
15. [15] Evans, T. ve Simpson, D., (2015). "Innovative Data Acquisition fort he Fall Cone Test in Tecaching and Research", Geoteknical Testing Journal, 38(3): 346-435.
16. [16] O’Kelly, B.C., (2013). "Atterberg Limits and Remolded Shear Strengh-Water Content Relationships", Geotech. Test. J., 36(6): 1-6.
17. [17] Skempton, A.W., Northey, R.D., The The Sensitivity of Clays, Geotechnique 3, 6, 539-543,1953.
18. [18] Youssef, M.S., El Ramli, A.H., El Demery, M., Relationship Between Shear Strength, Consolidation, Liquid Limit and Plastic Limit for Remolded Clays, Prof. 6th Int. Conf. for Africa on Soil Mech. Found. Engng, Montreal, 1, 126-129, 1965.
19. [19] Atkinson, J.H., Bransby, P.L., The Mechanics of Soils, McGraw-Hill, Book Company (UK) Limited, England 1977.
20. [20] Butterfield, R.A., Natural Compression Law for Soils Geotechnique, 29, 2, 84- 91,1979.
21. [21] Wood, D.M., Soil Behaviour and Critical State Soil Mechanics, Cambridge University Press, New York, 1990.
22. [22] Schofield, A., Wroth, P., Critical State Soil Mechanich, McGraw-Hill, New York, 1968.
23. [23] Karakan, E., Demir, S., (2018). "Liguid limit determination of various sand clay mixture by Casagrande and fall cone test method", Teknik Dergi, 20(2): 361-371.
24. [24] Gulen, M., (2019). Yoğrulmuş Killi Zeminlerin Kritik Durum Parametrelerinin Düşen Koni ile Belirlenmesi, Yüksek Lisans Tezi, Yıldız Teknik Üniversitesi Fen Bilimleri Enstitüsü, 2019.